linux/sound/core/seq/seq_fifo.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   ALSA sequencer FIFO
 *   Copyright (c) 1998 by Frank van de Pol <[email protected]>
 */

#include <sound/core.h>
#include <linux/slab.h>
#include <linux/sched/signal.h>

#include "seq_fifo.h"
#include "seq_lock.h"


/* FIFO */

/* create new fifo */
struct snd_seq_fifo *snd_seq_fifo_new(int poolsize)
{ … }

void snd_seq_fifo_delete(struct snd_seq_fifo **fifo)
{ … }

static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f);

/* clear queue */
void snd_seq_fifo_clear(struct snd_seq_fifo *f)
{ … }


/* enqueue event to fifo */
int snd_seq_fifo_event_in(struct snd_seq_fifo *f,
			  struct snd_seq_event *event)
{ … }

/* dequeue cell from fifo */
static struct snd_seq_event_cell *fifo_cell_out(struct snd_seq_fifo *f)
{ … }

/* dequeue cell from fifo and copy on user space */
int snd_seq_fifo_cell_out(struct snd_seq_fifo *f,
			  struct snd_seq_event_cell **cellp, int nonblock)
{ … }


void snd_seq_fifo_cell_putback(struct snd_seq_fifo *f,
			       struct snd_seq_event_cell *cell)
{ … }


/* polling; return non-zero if queue is available */
int snd_seq_fifo_poll_wait(struct snd_seq_fifo *f, struct file *file,
			   poll_table *wait)
{ … }

/* change the size of pool; all old events are removed */
int snd_seq_fifo_resize(struct snd_seq_fifo *f, int poolsize)
{ … }

/* get the number of unused cells safely */
int snd_seq_fifo_unused_cells(struct snd_seq_fifo *f)
{ … }